The exemplary embodiments relate generally to imaging or printing machines, and more particularly to controlling the concentration of toner in a development system of an electrophotographic imaging device to maintain a desired development performance. However, it is to be appreciated that the present exemplary embodiments will also find application in other types of devices where the concentration of toner and/or other materials used in the printing process is advantageously calibrated, monitored, or controlled.
In many related art printing and/or xerography systems, images are formed on paper and/or other medium using electrophotographic printing. A photoreceptive surface is electrostatically charged, and the image is transferred to the photoreceptive surface through selective exposure to light or other electromagnetic radiation. The light discharges the exposed areas of the photoreceptive surface to form an electrostatic charge pattern known in the art as a latent image. The latent image is developed by exposure to a developer material that selectively coats the charged surface areas.
A typical two-component developer includes toner particles and carrier beads. The carrier beads are usually several times larger than the toner particles. The toner particles triboelectrically bond to the larger, spherical carrier beads to form composite developer particles. In the vicinity of the electrostatically charged regions of the latent image, the toner particles are attracted away from the carrier beads and attach onto the photoreceptor due to the greater electrostatic attraction of the photoreceptor versus the triboelectric bonding to the carrier beads.
This developed latent image is referred to as the toner image. The toner image is transferred to the paper or other print medium using an electrostatic process to effectuate transfer of the toner particles from the toner image onto the paper. Finally, a fusing process employing heat and pressure permanently affixes the toner onto the paper or other print medium to form the final printed image.